Theme ‘temperature’

Theme ‘temperature’

‘Temperature’ is a theme in the chapter ‘Architectural spaces’ (see the recommendations).

Introduction
As is true for all warm-blooded animals, the body temperature of humans must remain more or less constant. Their core body temperature, namely that of the deeper tissue, can in fact only deviate a few degrees from the norm which is on average between 95.9°F and 100.0°F (Or 35,5 and 37,8 degrees Celsius).

When the ambient temperature is higher or lower than body temperature, the body perceives this and will begin to adjust itself in order to adapt to its surroundings. This can be done in two ways; consciously or unconsciously. Conscious (or semi-conscious) behaviour, can include actions such as (un)dressing, changing the desired temperature on a thermostat, moving outside or in, or simply drinking something that is warm or cold. Unconscious (or involuntary) physiological actions, like conscious behaviour, differ in manifestation depending upon the external temperature. When the ambient temperature is too low, our blood vessels will narrow, we shiver, we get goose bumps and chemical processes will speed up our metabolic rate, so we burn more calories. Alternatively, when the temperature is too high, our blood vessels will widen, we will start sweating, we can become more inert and our internal processes will slow down our metabolism. However irrespective of the different expressions, what is common about all of the actions and behaviors is that they represent the body trying to regulate its own internal temperature.

For any one person, a preference or need for a specific temperature can vary depending on the time of day, their routine and activity level. Variation between people can be even more marked due to physiological differences including age, gender and body type, in addition to genetic, cultural and climate susceptibilities and predispositions. Surroundings that are too cold or too hot can have a substantial influence on a person’s mood and ability to function. When too warm, people can become irritable and socially intolerant; their performance levels drop and they tend to sleep less well. Alternatively, when too cold, staying alert or awake can become difficult. Therefore, ‘thermal comfort’ is of great psychological and social importance.

Autism and ambient temperature
People with autism are often over (hyper) and or under (hypo) sensitive to temperature and therefore, understandably, may get over or under-heated. In the complex chain from temperature perception to behavioral and physiological corrections, those with autism do not differ widely from other people. However for the person with autism, those small differences can have a profound effect.

The perception of ambient temperature is part of the extremely complicated human tactile system. In the body, there are sensors directly below the upper skin layer that are specialized in temperature detection alongside other sensors with different primary tasks that also contribute to some temperature sensing. Subsequently, impulses are sent via the spinal cord to the thalamus, the gateway to the cortex which sorts incoming sensory stimuli. This then relays information to the sensorimotor cortex that identifies the body part from which the signal has originated. (See Linden and also Dunn.) For people with autism, there are most probably neither threshold-differences in the primary sensation of temperature, nor in the transmission of that information to the sensorimotor cortex. Hence the physiological corrections associated with temperature change, such as the widening or contraction of blood vessels, are also unaffected. People with autism sweat, shiver and have goose bumps, just the same as anyone else. However, potential problems can develop in the corrective or semi-conscious behavior of those with autism. As with (almost) all sensory abnormalities of people on the spectrum, there can be deviations in the communication between brain cells. This can lead to modulation problems, comparable to the volume regulation of a sound system. The warmth or coldness signal registered by the body can be too weak (hypo-) or too strong (hyper-sensitivity) in relation to the strength of the stimulus. It is also possible that a person with autism may confuse the signals for cold and for heat. In this case, we can speak of a diverging temperature perception. Thus, for the person with autism, these factors may be the cause for an inadequate understanding of their thermal reality and subsequent defective corrective behaviors such as putting on more clothes or turning down the heat when alternative actions might be expected.

Hence, in the daily life of people with autism, this diverging temperature perception can lead to many difficulties which can only in part be solved by measures of temperature regulation and the heating and cooling in homes and buildings.

In the family home
In a family, over- or under-sensitivity to warmth and cold may mean that the autistic family member systematically feels colder or warmer than the others. If combined with a lack of empathy or understanding in this respect, conflicts may arise over the ideal temperature in the home. That for instance might lead to disagreements over the correct setting for a thermostat or whether windows and curtains should be open or closed.

It can therefore be wise to first recognize and then to agree to the preferences of the family member with autism, but this should not be at the expense of the thermal comfort of the others. In day-to-day family dealings, one is well advised to avoid making a big fuss about this. Allow perhaps that windows be opened once in a while, serve ice-cream occasionally, move the mattress to a cooler or hotter spot if desired, or be creative in other ways. Concerning the architectural and technical properties of the home, one should try to strive towards thermal comfort within narrow limits, recognizing that the preferences of the non-autistic family members who have no divergent responses to the ambient temperature, can be beneficial to the autistic member, if considered in a sympathetic manner.

In an institution
In the Kannerhouse youths wear T-shirts in winter and fleece sweaters in summer. Menno has a diverging temperature perception and therefore puts on his shorts each year by the calendar on June 21st . Others go through the same rituals summer and winter in the same tempo, instead of taking it easier in summer. In their own room they tend to have their heating very high or very low the year round. Also they don’t always understand one may get overheated such as from solar gain when the sun is on the windows for a long time.
Because of the large individual differences in temperature experience there aren’t many recommendations that hold for everyone. Generally, the wisest solution is to take measures which promote the general thermal comfort and discourage or forbid residents to deviate too much from this.

At school
With regard to schools, the Dutch Health Council limits itself to general statements such as that for 45% of teachers, it is ‘often’ too warm in the classroom in summer and that in a school setting, high temperatures can lead to unease, headaches and fatigue for everyone. Whilst it hesitates on the effect that temperature might have on school performance, according to a review publication by Delft University of Technology, there is broad consensus that school performance is negatively affected by unfavorable temperatures.

Currently, guidelines in the Netherlands stipulate that the temperature range of a classroom should be between 66°F (the lower limit; 19°C) and 77°F (the upper limit; 25°C). However this is of limited value. It would be extremely rare that the average temperature of a classroom would be outside these parameters for a whole day. Alternatively, it would be better if there was a limit on the percentage of time in a day that the limits could be exceeded.

In naturally ventilated classrooms, even without pupils, temperatures can fluctuate widely. Temperatures can be influenced by factors such as the height and depth of the room, warming or cooling of classroom surfaces, incoming sunlight and local air currents. Lowest classroom temperatures commonly occur at the beginning of the day. Over the course of the day temperatures then tend to increase due to radiant heat from pupil activity and electrical equipment. Often classrooms can become too hot.

In order to arrive at a rough estimate of the temperature conditions in Dutch schools, we conducted a secondary analysis of research in nine Dutch schools. This led to a conservative estimate, that on average it is too warm (or much less frequently too cold) in almost 40% of Dutch schools at any given moment. Whilst hyposensitive students will not consciously find these conditions unpleasant, it does not mean to say that it will not affect their well-being, not least as the temperature may be mal-affecting the mood and behavior of their peers and teachers. The less common hypersensitivity to heat, cold or both implies that the negative effects of exceeding the temperature standards will be intensified and would therefore have a much stronger negative impact on autistic students than it has on others. In such cases, autistic students, due to their temperature experience, will regularly request that the heating be turned up or down or that windows be opened or closed. It is therefore important that teachers are aware of this, so that they can respond appropriately and sympathetically to such requests.

General recommendations
The message in all these contexts is the same:

It is important that parents, counselors, therapists, teachers and others who deal with people on the spectrum, are aware of their potential deviating temperature perception.

Making allowances for special preferences regarding temperature is advisable, as long as the general thermal comfort for others does not suffer.

The architectural and technical properties which affect the indoor temperature should aim at keeping thermal comfort within narrower than usual limits.

climate

One study even found differences in preferred classroom temperature between English (61,7°) and Singaporese (83,8°) students of more than 22° F. See Brager, Gail S., Richard J. de Dear, ‘Thermal adaptation in the built environment: a literature review’, In: Energy and Buildings 27(1998) 83-96. Samenvatting/vindplaats URL.

ambient temperature

Here it is about the indoor environmental temperature. Other instances of diverging temperature perception which may lead to getting burned by radiators, hot water or stoves, will be dealt with elsewhere.